master 90bfb1075d1: Treat empty mailto URIs properly under Android

[Po Lu]

branch: master
commit 90bfb1075d1615da7f80432d6c3465210bb96f0d
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Treat empty mailto URIs properly under Android
    
    * java/org/gnu/emacs/EmacsOpenActivity.java (onCreate): If an
    empty mailto: URI is supplied, ascertain if EXTRA_EMAIL is set,
    then derive a mailto URI from that if so.
---
 java/org/gnu/emacs/EmacsOpenActivity.java | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/java/org/gnu/emacs/EmacsOpenActivity.java 
b/java/org/gnu/emacs/EmacsOpenActivity.java
index 0c0da6acd1f..f0f1068d3e2 100644
--- a/java/org/gnu/emacs/EmacsOpenActivity.java
+++ b/java/org/gnu/emacs/EmacsOpenActivity.java
@@ -462,10 +462,30 @@ public final class EmacsOpenActivity extends Activity
            /* Escape the special characters $ and " before enclosing
               the string within the `message-mailto' wrapper.  */
            fileName = uri.toString ();
+
+           /* If fileName is merely mailto: (absent either an email
+              address or content), then the program launching Emacs
+              conceivably provided such an URI to exclude non-email
+              programs from being enumerated within the Share dialog;
+              whereupon Emacs should replace it with any address
+              provided as EXTRA_EMAIL.  */
+
+           if (fileName.equals ("mailto:";))
+             {
+               tem = intent.getCharSequenceExtra (Intent.EXTRA_EMAIL);
+
+               if (tem != null)
+                 fileName = "mailto:"; + tem;
+             }
+
+           /* Subsequently, escape fileName such that it is rendered
+              safe to append to the command line.  */
+
            fileName = (fileName
                        .replace ("\\", "\\\\")
                        .replace ("\"", "\\\"")
                        .replace ("$", "\\$"));
+
            fileName = "(message-mailto \"" + fileName + "\" ";
 
            /* Parse the intent itself to ascertain if any